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Monday, April 18, 2016

Huntleya fasciata

All the huntleyas are wonderful, but this species, Huntleya fasciata, became an obsession for me after we flowered it for the first time a few years ago. The flowers are thick and glossy and the color of candy apples.

And unlike the flowers of Huntleya wallisii, which seems to appear like a magnificent solitary comets, these pop up like dandelions.

Check out the claw at the base of the lip. Elaborate lip fringe is a hallmark of the Huntleya clade (Pescatoria, Chondroscaphe, Kefersteinia, Chaubardia, etc.).

Our huntleyas are permanent residents of the fog zone immediately adjacent to our propagation benches, the only place we maintain humidity continuously in the 80 to 95% range. I like to grow them in slatted wooden baskets which fall apart naturally after a couple of years and are easy to remove with minimum root disturbance. Huntleyas and their relatives hate root disturbance, and although the fan-shaped growths look like promising candidates for division, the success rate is not high, even when the divisions consist of multiple fans. Fortunately, huntleyas are selfed readily and produce nice fat capsules. I hope to have a crop of fasciata seedlings for distribution in a couple of years.

Wednesday, April 13, 2016

Gongora gratulabunda

There is only one species (or section if you accept flaveola and similis) in the genus Gongora that has this wonderful serpentine kink near the base of the lip: gratulabunda. The flowers are large for a Gongora and widely spaced. It is instantly recognizable and one of my favorites. G. gratulabunda grows as an epiphyte in wet tropical forests along the Pacific coast of Colombia at 850 to 1600 meters elevation. Rudolf Jenny states in his Monograph of the Genus Gongora that it is one of the rarest of the genus.

After at least three attempts I finally managed to set a capsule on one of our gratulabunda accessions. Most of our gongoras resist pollination by hand, at least when the pollinia are freshly released from the anther. Over and over again they seem to want to spring back out of the stigmatic cavity like a rabbit eared jack-in-the-box. Lately I've been letting Gongora pollinia dry for 30 minutes before placing it in the stigmatic opening with a little more success. Gratulabunda means 'wishing luck' which sums up my hopes for our new gratulabunda seedlings.

Wednesday, March 9, 2016

At Last, Flowers

I could hardly believe it. Flowers? On our Mischobulbum? My first impulse was to seize the label to check the date of acquisition. Little Mischobulbum sp. 20071376 has labored for eight long years to produce this delicate inflorescence. Congratulations, little plant.

Grateful as I am for the flowers, it seems to me that ninety-nine percent of this orchid's coolness resides in the vegetative part of the plant -the terete pseudobulbs, like chubby green fingers, and the heart shaped leaves. No other orchid in our collection looks remotely like this.

Mischobulbum is not a universally accepted genus. Some authors fold it into the Asiatic genus Tainia. Mischobulbum species are terrestrial, with creeping rhizomes and terete pseudobulbs of one internode, spaced between one and three centimeters apart. A single cordate leaf emerges near the top of the pseudobulb. There are eight species from Thailand, peninsular Malaysia, Borneo and Sumatra. They are not common in cultivation, so this is a prized plant in our collection.

Wednesday, March 2, 2016

Orchid Daze 2016: How We Did It

This year's orchid display is the most ambitious and technically demanding orchid display that we have ever done. In January we set up shop in the Orchid Atrium to create the grapevine Orchid Spheres.

Each of the grapevine spheres, which measured 3, 4 and 5 feet in diameter, took about three hours to make. The orchids were prepared in advance. To prep each pot, we drilled additional holes in the sides of each pot to allow water entry. To allow the pot to be inverted, each plant was secured in its pot with rubber bands. The top dressing of cocoa fiber retains the medium in the pot when it is inverted.

Jason attaches a Cattleya pot to the grapevine sphere using one inch clips.

Sarah attaches moss to the sphere with bonsai clips that we made from hanging basket wire.

Cattleya and Miltoniopsis orchids on a finished sphere. Our designer, Tres Fromme wanted an airy open look for the spheres, and in places, you can see through them.

Getting ready to hang one of the small spheres with pulleys, chain and a lift. There are eight orchid spheres in the Orchid Atrium scattered at various heights. The orchids in the spheres will need a switch out after several weeks, so we are using portable scaffolding on wheels to access the spheres.

Orchid Daze 2016 runs through April 10. Stop by and see us!

Saturday, February 20, 2016

Spotted Slipper

The Philippine islands have a fairly diverse slipper orchid flora, with about ten distinctive species. The most extravagantly spotted species, Paphiopedilum haynaldianum grows on rocks and occasionally as an epiphyte from sea-level to about 1400 meters on several of the larger islands.

The Philippine climate has three seasons which can be tricky to emulate in the greenhouse: a hot dry spring when temperatures can reach 90º; a very rainy summer; and a cool somewhat drier winter when temperatures can drop into the 40's. Our plants do reasonably well in a warm greenhouse that reaches 85º in summer and falls into the low 60's at night in winter.

Spotted multifloral Paphiopedilum haynaldianum is easily confused with its sister species, P. lowii, which grows as an epiphyte on the neighboring islands of Borneo, Sumatra, Java and Sulawesi, and on peninsular Malaysia. P. haynaldianum is distinguished by a longer narrower dorsal sepal, more spots and a peduncle that is villose (having long hairs) rather than shortly pubescent. You can see Paphiopedilum haynaldianum on display now in the Orchid Display House.

Friday, February 12, 2016

Yellow Slipper

The Plant List records 30 different named varieties as synonyms of Paphiopedilum insigne, most of them published by Pfitzer in 1903. Even if most of these are color variants that don't deserve varietal status, the large number suggests a fair amount of variability, particularly for a species distributed over an area smaller than the state of New Hampshire.

The state of Meghalaya in north-east India, home to Paphiopdilum insigne, is considered among the richest botanical and zoological habitats in Asia. It has a diverse topography. Seventy percent is forested with tropical and subtropical vegetation, and there are significant tracts of primary forest. Some areas in Megahlaya are among the wettest places on earth, receiving 472 inches (12,000 millimeters) of rain per year. It is exactly the sort of place where one expects to find high biodiversity.

Like many other slipper orchids, Paphiopedilum insigne has its own preferred niche. It grows on dolomitic limestone outcrops near waterfalls and in light shade of shrubby vegetation at elevations between 1000 and 1500 meters.

We received the plant above as Paphiopedilum insigne var. sanderae (Wallich ex Lindley) Pfitzer. It has canary yellow flowers with green veins and purple specks on the dorsal sepal. This is one of the prettiest yellow slippers in our collection and I'm happy to report that we have a capsule developing on one of our plants. It will be interesting to see how much variation there is among the seedling offspring.

Thursday, February 4, 2016

The Tricks in gratrixianum

Slipper Orchid pouches attract a lot of attention around here from our visitors. And so, from the Department of Frequently Asked Questions comes: Are Lady's Slipper Orchids carnivorous? Is the pouch a trap? 'No' and 'Sort of' are the answers. That glossy bubblicious pouch, actually a modified petal, is a trap for insects, but the trap has a different function from the traps of insectivorous plants. The pouch is just one of the parts of a pollination mechanism, a reproductive process in which a successful outcome is pollination, not nutrition. And the insect is the messenger, not the meal.

Paphiopedilum gratrixianum, a tropical Asian slipper flowering now in the Orchid Center, is an example. Tropical slipper orchids are thought to be pollinated by flies, though most of the evidence is indirect. There simply aren't a tremendous number of field studies documenting slipper orchid pollination. So, although I don't know exactly which insect pollinates Paphiopedilum gratrixianum, it's possible to make a fair guess, based on a study of a closely related species, Paphiopedilum villosum. A field study (Bänziger 1996) of P. villosum reported pollen capture by hover-flies and the author suggested that the hover-flies are lured by food deception.

The shimmering staminode (the flattened end of the column) in the center of the flower appears to mimic the sugary honeydew secretions of aphids. To a hover-fly, it holds the prospect of a meal. Something nutritious and delicious. But, no, it's simply a slippery surface, and the hover-fly falls into the pouch.

The margins of the pouch (above) are rolled inward and prevent the fly from taking wing. To escape, the fly has to climb the scaffolding of hairs behind the column where the pollen is located. The pollen sticks to the back of the fly as it emerges near the base of the column. The fly receives nothing that it can use, no supper, just a enormous blob of pollen that can be deposited at the next slipper orchid offering a fake meal.

Pollination using a food lure (real or fake) is a fairly common mechanism across the plant kingdom and involving different types of pollinators. But in orchids, the anatomy for deception and manipulation of winged insects has evolved to an extraordinary degree. Yes, the pouch is a trap, but in the same way that the bucket of a Coryanthes flower is a trap. It's a trap that facilitates pollination.

Monday, January 25, 2016

Snow Day

Paphiopedilum victoria-regina
We were spared Snowmageddon. The storm that paralyzed most of the East Coast stopped at our doorstep, hurled a handful of sleet at the greenhouse panes, and left. What a relief.

Not that we will be spared the fallout, though. Dozens of boxes of orchids for our Orchid Daze display are supposed to ship into east coast airports this week, a risky proposition that makes me break out in a sweat just thinking about it.

While I water, I wonder how our colleagues at botanical gardens in New York, Brooklyn, Washington and Virginia are faring. And Kennett Square, too, though I wonder if Longwood might not own more snowplows than the city of Atlanta. The problem facing any greenhouse grower under these circumstances (besides what's going on at home) is that greenhouse plants don't recognize snow days or weekends or holidays. There will always be plants that need water. Someone has to be there every single day. I can only hope that someone at each of these gardens lives close enough to walk in. And that the power stays on. And the back up generators fire up on cue.

Good luck to everyone having the 'Snow Day' experience. Stay safe.

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